In the fur industry, animal pelts are often stretched in a non-destructive way in order to maximize the size of the pelt. The pelts define a substantially tubular shape and have an outwardly oriented fur side and an inwardly oriented leather side. The stretching is taking place after skinning the animal and scraping off the layer of fat on the leather side of the pelt and before the drying of the pelt. In the present context, the word pelt is understood to encompass pelts of minks, foxes and similar small mammals. The pelts are often stretched on a pelt board, which is nowadays made of plastic. Normally, the leather side of the pelt is facing the surface of the pelt board and the pelt board may in addition be provided with a fat absorbing material such as a paper bag or sleeve, which is in contact with the leather side of the pelt. The fur side of the pelt is thereby facing outwardly during the stretching and drying of the pelt.
The stretching procedure and the use of pelt boards are known per se and both are disclosed in e.g. WO 2005/028682 A1. Therein is disclosed the use of a gripping element which is brought in engagement with the whole periphery of the pelt and the drawing of a fixing bag over the outside of the pelt in order to maintain the pelt in a stretched configuration during the drying of the pelt. Thereby, the previous use of staples and the thus produced elongated holes in the pelts may be avoided.
In relation to the above terminology, the word bag which in its normal understanding may describe a sleeve with a closed off bottom should in the present circumstances and further along in the present patent application be understood to also encompass sleeves which are not closed off and which have a tubular or cylindrical shape without a closed off bottom.
WO 2006/026986 A1 discloses a help arrangement for clamping the nose end of a pelt to a pelt board.
WO 2007/033681 A2 discloses a method and machine for the folding out of the tail part of the pelt in connection with the stretching of the pelt on the pelt board.
WO 2008/025364 A1 relates to a method and machine for performing water brushing of tanned pelts in order to achieve a more presentable appearance of the pelt.
WO 02/44428 A1 relates to another method and machine for stretching of a pelt on a pelt board. The pelt is secured in the stretched positing by means of a sleeve or bag which is drawn over and around the pelt board, so that the pelt is pressed and locked against the pelt board. This method, which is also described above, is nowadays used as standard method for fixing the pelt in the stretched position in a non-damaging way.
DK 169 525 B1 discloses a machine for stretching a pelt. The machine includes a gripping mechanism for holding the pelt. Magnetic sensors are used for controlling the extent of stretching of the pelt by the gripping mechanism.
DK 2000 01174 L discloses another method in which the stretched pelt is held in place in a non-destructive way by the use of a pelt bag or sleeve.
EP 2 818 563 A1 discloses a hair controller for mounting on a stretching machine. The controller utilizes a nozzle or orifice for providing a stream of air.
US 2003/0019255 A1 discloses yet another method for fastening a pelt on a pelt board after stretching by the use of a sleeve or bag, and a corresponding sleeve for use with the method.
WO 2008/022644 A1 discloses a tube-shaped holding bag, which is drawn over the fur side of the pelt for holding the pelt in a stretched position.
WO2005/080607 discloses a method and an apparatus for fastening a fur on a pelt board by the use of a stretchable wrapping foil supplied from a single foil reel.
WO 2012/126467 discloses a technique of determining the maximum force to which a pelt may be exposed by measuring the initial lengths of the pelt prior to applying a stretch force to the pelt and predicting the maximum allowable force to be applied to the pelt from the initial length.
WO 2015/024788 discloses an apparatus and a method for stretching a pelt according to which method and in which apparatus the speed with which the pelt is stretched is gradually reduced during the stretching of the pelt.
It has been realized that by stretching of the pelt according to the above prior art technologies by gripping the lower end of the pelt, i.e. the tail end of the pelt, most of the stretching force is applied to the lower part of the pelt, i.e. the part of the pelt closest to the tail end of the pelt, and less force is applied to the upper part of the pelt, i.e. the part of the pelt which is closest to the nose part of the pelt. This is contrary to the anatomy of the pelt since the upper part of the pelt would normally be capable of withstanding a larger force than the lower part of the pelt. The pelt will thus not be stretched in an optimal way by applying the stretching force to the lower part of the pelt. It is thus an object according to the present invention to provide technologies for properly stretching of both the upper part of the pelt as well as the lower part of the pelt.
Further, in connection with the stretching of the lower part of the pelt it has been realized that placing the pelt board including the pelt in a proper stretching position is difficult due to the fact that the gripping mechanism, which is intended to fasten the pelt about its complete contour, i.e. both the back side contour and leg side contour, obstructs the access of the user. Thus, it is an object according to the present invention to provide technologies for simplifying the access of the user to the stretching apparatus.
Yet further, it has been realized that the stretching operation and in particular the fine tuning of the gripping mechanisms require the user to hold one hand on the pelt while the other hand is operating the user interface of the stretching apparatus. This is disadvantageous in relation to the alignment of the pelt in the stretching apparatus and it would be advantageous if the user could be able to use two hands holding the pelt instead of only one hand. Thus, it is an object according to the present invention to provide technologies for allowing the user to operate the stretching apparatus while keeping both hands on the pelt.
Still further, it has been realized that the wrapping operation performed by using a single stretchable wrapping foil is suffering from serious drawbacks, in particular in relation to the speed of the operation and the physical impact on the pelt board and the fixation of the pelt board by stretching the wrapping foil during the wrapping operation. Thus, it is an object of the present invention to provide technologies for allowing an improved fixation of the pelt relative to the pelt board in relation to speed and fixation strength as compared to the prior art single foil wrapping technology.
Still further, it has been realized that the non-symmetrical structure of a pelt, in particular a pelt from a mink or similar skinned animal is inhomogeneous and for this reason, the difference in strength of the pelt when exposing the pelt to the stretching operation may cause bending of the pelt board, which in the first place exposes the pelt board to excessive forces and in addition, may cause an incorrect stretching of the pelt, which incorrect stretching does not establish the intended shift of the length from one class to another.
Still further, it has been realized that the stretching of the pelt may advantageously be combined with a fur processing step such as a step of brushing the fur side of the pelt, using rollers for properly orientating the hair of the pelt, or a comb for orientating the hair of the pelt in an intentional and proper orientation prior to or after the stretching of the pelt by using the pelt stretching apparatus.